Under modern packaging practice, molded flexible walled plastic containers are widely used for packaging a variety of products, particularly liquids such as water, cleaning agents, anti-freeze and the like.
When such containers were first introduced they were commonly labeled by silk screen printing techniques. However, that procedure has limited applicability due to inherent high cost, limitations on multi-color applications, and the necessity for warehousing or storing preprinted containers in order to provide an adequate inventory and thus inherently relegating the unfilled preprinted containers to specific product usage.
More recently, preprinted plastic labels, formed as endless tubular bands, have gained popular acceptance due to low cost, compactness for storage, and their ready adaptation to relatively low-cost offset or similar printing processes. With the advent of such preprinted tubular labels, it is no longer necessary to store or warehouse preprinted containers since a supply of blank containers may be readily adapted to a variety of products simply by applying the appropriate band label thereto. Normally such band labels are formed from thin flexible plastic film having the opposing ends thereof heat sealed or bonded to form an endless band. Preferably a multiplicity of such tubular band labels are formed end-to-end from an elongated tube which is then printed and stored in a collapsed state, usually in a roll form, with the individual label bands being delineated by perforations or other parting means so that they may be removed one by one from the leading end of the storage roll.
In the early use of such band labels, the same were applied by hand, fitting them over the exterior of the containers, frequently stretching tight fitting labels or gluing loose fitting labels to hold the same in a desired display position. With the advent of heat shrink plastic films for band labels, heat shrinking techniques were readily adapted for anchoring the labels in place about rigid walled, as well as flexible walled, containers.
Since the hand application of the band labels is time consuming and costly, devices for assisting and accelerating the label application techniques were developed, as typified in U.S. Pat. Nos. 3,811,986 issued May 21, 1974 and 3,850,777 issued Nov. 26, 1974. Certain mechanical devices also were developed for at least semi-automatically opening the label bands and applying the same to the containers. See, for instance, the opening apparatus set out in U.S. Pat. Nos. 3,792,807 issued Feb. 19, 1974 or 3,551,258 issued Dec. 29, 1970 and 3,523,052 of Aug. 4, 1970.
In general, it may be stated that while previously known devices and mechanisms of the prior art have gained commercial acceptance, the need for a fully automated apparatus, capable of positive, fast application of tubular labels in a reliable manner, still exists. It is to that area that the current invention is directed; the same embodying improved operational concepts and mechanisms for the automatic opening and application of tubular labels about containers, particularly flexible walled plastic containers, although the concepts and teachings thereof are readily adaptable to applying band containers, of heat shrinkable plastic for instance, about rigid walled containers as well.